our back, things could get really bad, particularly for the unvaccinated. >> reporter: authorities are urging caution with a new study making headlines tonight, that if true may partially explain why omicron is so transmissible. researchers at the university of hong kong estimate that the omicron virus could multiply 70 times faster in the bronc y'all tubes than delta. the study has not yet been made public for review. today, long lines for testing. new york city bracing itself with a spike in numbers. nearly 3,800 new covid cases every day. >> it is clear that the omicron variant is here in new york city, in full force. >> reporter: the city planning to distribute home covid tests and kn-95 masks, urging residents to upgrade or double mask. covid cases forcing broadway shows like the tina turner musical and "hamilton" to cancel